package main
import "fmt"
import "strings"

func m(input rune) rune {
	switch {
	case  input>='a' && input <='z':
		return 'l'
	case input>='A' && input<='Z':
		return 'U'
	default:
		return -1
	}
}

func main() {
	s:=strings.Map(m, "abc123DEF")
	fmt.Println(s)
}
